Personalizing Lung Cancer Treatment With Immune-Based Therapies
Research Advances Immuno-oncology is the most exciting development in cancer treatment in recent memory, if not ever.
y giving our own immune system the ability to fight cancers the same way they fight viruses like the common cold, these new therapies are opening doors to a future where cancer treatment is much simpler and more effective than it has ever been.
The results, across a range of cancers from lung cancer to melanoma to bladder cancer, have been staggering, with many patients making complete recoveries, even from late-stage disease. “Doctors are reluctant to use the term ‘cure’ when it comes to cancer,” says Katherine Bonter of the Personalized Cellular Immunotherapy Project, Hôpital Maisonneuve Rosemont. “But these immunotherapies are much closer to being an actual cure than anything we’ve had before.”
No one-size-fits-all solution
Each immunotherapy, however, is only active against a specific type of cancer and molecular testing is needed to identify the type prior to treatment. There is a way of knowing before treatment – that is through molecular testing of the tumor. “The crux of immuno-oncology right now is antibodies,” says Bonter. “And antibodies target a specific protein. So you need to be able to look at the tumour and make sure that it is in fact expressing the specific protein that your drug targets.”
One of the most exciting applications of immunotherapy is in lung cancer patients. Lung cancers are extremely diverse. The variety of lung cancer one patient has can be radically different from the variety another person suffers from, making tests that can help doctors choose the most effective treatment extremely valuable. “Within lung cancer we’ve identified more than a dozen different mutations and now have drugs that are being paired to these individual mutations,” says Dr. Rosalyn Juergens of the Juravinski Cancer Centre at McMaster University. “These paired targeted therapies have dramatically increased the amount of time some people can live with a diagnosis of lung cancer.”
With the advent of a new biomarker test, specifically regarding expression of the protein PD-L1, it is becoming possible for the first time to predict which patients have a higher chance of responding to immunotherapy and which would be better served by an alternate treatment. These tests are still young, but research and development are ongoing, and the potential for them to bring personalized medicine to immuno-oncology is very promising.
Because lung cancer can be very aggressive, every treatment decision is one of weighing the benefit of each given therapy versus the risks of thus delaying other therapies. At any stage, when choosing between immunotherapies and other treatments like chemotherapy, information about the protein expression of the cancer could very well tip the balance one way or the other. “The chance of immune-based therapy working with no knowledge is somewhere in the range of 15–20 percent” says Dr. Juergens. “If I know a patient is PD-L1 positive at a high level, the chance of the drug working can suddenly become double or triple that.”
Dr. Juergens is quick to add that the current tests have limitations in their ease of administration and predictive powers, impeding their current application in clinical settings. She is hopeful, however, that upcoming clinical trials and further development will continue to advance and improve these new tools in the future. That would be very good news for patients with all types of cancer, allowing the proliferation of new treatment options to be matched with knowledge of which to use when, and on whom, for the best effect.
Overall, the future of cancer treatment is very bright, with immuno-oncology and personalized medicine being a big part of why. “It couldn’t be a more exciting time to be a lung cancer doctor,” says Dr. Juergens. “I can’t wait to see where the future takes us as all these different therapies are coming to light.”